How to stop one chicken from injuring another?

Maybe I should have posted this in the injury forum but I thought it may be appropriate to put it here too. I have only six hens. One hen, a brahma has sores on her feet that I am sure come from one of the other hens pecking at her. She is not the top hen but is not at the bottom of the pecking order either. She is the most 'polite' of them all. I have also noticed that the meanest bird I have 'an easter egger mutt' is pecking at the red dried blood marks on the feet of the brahma.

Is there something that I can do to either change behavior of the biting chicken or to make the injured hen less likely to be pecked? The injured hen does not want to come out of the coop because of the bad hen that will bite her.

I dont really have an interest in using my hens for meat but I really detest bullies of all types... even hens. My thoughts are coming close to snapping the neck of the offender. Thanks for any suggestions!